Aim3D introduces Voxelfill 

Aim3D has announced details of its Voxelfill process for sustainably improving the strength properties of a layer-based 3D component, alongside the launch of a new 3D printer, the ExAM 510.

Aim3D was set up in 2017 as a spin-off company of the German University of Rostock. The company has set out to develop 3D printers that could replace injection moulding whilst using the same pellets that are commonly used for injection moulding so that users would have a range of existing materials with known properties to choose from. Aim3D makes use of two processes: Fused Granulate Moulding or FGM for plastics, which is similar to the widely used Fused Filament Fabrication approach but with pellets rather than filaments; and Composite Extrusion Moulding or CEM for metallic and ceramic injection moulding pellets, which uses a process similar to Fused Deposition Modelling but follows this with a sintering stage to dissolve the binder and bond the particles together.

However, Aim3D suggests that the nature of 3D printing – building parts up one layer at a time – inherently leads to components with inhomogeneous strength properties, meaning that they are more brittle along the Z axis than the X and Y axes, at least when using polymer materials.

So the new Voxelfill process is designed to overcome this for printing plastics, metals and ceramics. The idea is to use cross-layer filling, essentially injecting thermoplastic material with the extruder into cavities in the lattice structure used to build the part being manufactured. However, this is not simply filling all the cavities, or voxels, in one plane but instead uses a more distributed pattern that’s said to result in a ‘brick-like bond’ in the part. This should lead to both greater strength and improved elasticity in the Z-direction of the parts being printed. Moreover, this additional material reduces the overall printing time required.

It can be used with different materials, and by varying the materials used for the Voxelfill, it’s possible to create multi-material parts for the inner walls to tweak the material properties. That could mean tailoring the weight, damping properties, elasticity or changes to the centre of gravity for each individual part being printed. Also, it’s possible to use the Voxelfill more in some areas than others to vary the properties in different parts of an object. 

Voxelfill can also be used with fibre-reinforced materials, with the option to align the fibres to enhance mechanical properties of the part.This can already be done on the flat areas but with Voxelfill it can be extended to the contour and the inner walls of the component and should also improve the object’s mechanical properties.

Clemens Lieberwirth, CTO at AIM3D, commented: “Of course, the Voxelfill process is particularly suitable for 3D printing of plastics and fibre-filled plastics, but it is also suitable for 3D printing of metal and ceramic components using the CEM process. In general, there are advantages due to the higher build speed and cross-layer filling.” 

As for the new ExAM 510, a prototype was shown off at last year’s Formnext show and the commercial launch is planned for this year’s K and Formnext shows. The company has stated that it developed the ExAM 510 to get more out of its patented extruder technology, which allows for output of up to ten times higher than standard filament extruders. The machine uses linear motors and features a stable mineral cast bed for very precise operation at high speeds. Essentially, it is a larger version of the existing ExAM 255. It has a larger build area of 510 x 510 x 400 mm and a faster build rate, depending on the material, of up to 250 cm³/h (when using a 0.4 mm nozzle).

The ExAM510 can print up to three different materials in parallel, which allows for two building materials and a support material. It uses two CEM pellet printheads and a filament printhead. The build area can be heated up to 200°C in order to reduce stresses in the component and to process high-performance materials. This makes it possible to also process high-temperature plastics such as PEEK, PEI, PSU, PPS, with or without fibre filling. It will also handle a range of metals, including 316L, 17-4PH, 8620, 42CrMo4, 304, 420 W, WcCo, Ti64, Cu99, as well as ceramics including Al2O3, ZrO2, SiC, Si3N4. 

You can find further details of both the Voxelfill technology and the ExAM510 from aim3d.de.